16423621 has 2 divisors, whose sum is σ = 16423622. Its totient is φ = 16423620.

The previous prime is 16423609. The next prime is 16423637. The reversal of 16423621 is 12632461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13322500 + 3101121 = 3650^2 + 1761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16423621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16423681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8211810 + 8211811.

It is an arithmetic number, because the mean of its divisors is an integer number (8211811).

Almost surely, 2^16423621 is an apocalyptic number.

It is an amenable number.

16423621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16423621 is an equidigital number, since it uses as much as digits as its factorization.

16423621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 25.

The square root of 16423621 is about 4052.6066919947. The cubic root of 16423621 is about 254.1887379322.

The spelling of 16423621 in words is "sixteen million, four hundred twenty-three thousand, six hundred twenty-one".